PHOENIX -- The United States Supreme Court Monday handed down its ruling on Arizona’s SB-1070.

The nation’s high court struck down much of the bill, but kept the most controversial portion in place, for now.

In its simplest terms the ruling means police may still inquire into citizenship, but they cannot arrest or detain someone based on their immigrant status. It is no longer a state crime if an immigrant is not registered with the state. Undocumented immigrants can seek employment in the state of Arizona. Finally, law enforcement officials can no longer do immigration sweeps, if the only illegal activity is an undocumented alien being present in the state.

“Those law enforcement officials who have been arresting or detaining people because they think they are here illegally have to stop doing that. It is not and cannot be a state crime to be in the country illegally,” said constitutional law expert Paul Bender, who teaches constitutional law courses at the Sandra Day O’Connor College of Law at ASU.

Absent from the 5-3 opinion, authored by Justice Kennedy, was Justice Kagan, who took no part in the decision because of her connections to the Department of Justice.

The ruling struck down provisions of the law that made failure to comply with federal alien-registration requirements a state misdemeanor, that made it a misdemeanor for unauthorized aliens to seek work in Arizona, and that allowed Arizona law enforcement to arrest a person without a warrant if they had probable cause that person had committed any offense that made them deportable.

However, still in place is the so called “show me your papers” portion of SB-1070.

"The state of Arizona cannot create immigration statutes that penalize undocumented immigrants criminally,” said immigration law expert Evelyn Cruz, who teaches immigration law courses at the Sandra Day O’Connor college of law at ASU.

However, the most controversial portion of the bill is still in place, which means that Arizona law enforcement may still inquire into immigrant status. That inquiry, though, must be connected to some other wrong doing.

“You can only arrest them for something else, and while you’ve got them for something else, you can look into immigration status,” said Bender.

In short, the ruling means that while Arizona law enforcement can inquire into immigration status, they can no longer do anything about it without the permission of the federal government.

“The problem for the state of Arizona following that inquiry is that they cannot then proceed to arrest them,” said Cruz, “If the federal government declines to take the person into custody, the state of Arizona cannot arrest that person.”

Bender says this sends a clear message to the states that the federal government is in charge of enforcing immigration policy.

“This is a ringing assertion of exclusive federal authority in the immigration area,” said Bender.

Bender also says just because the Supreme Court upheld the provision allowing police to ask for documentation, does not mean that it is Constitutional. He says that the police can now experiment by asking for proof of citizenship, but if they cannot do that without racial profiling, SB-1070 will be back before the courts.

“There’s no question that this is a defeat for 1070 and a victory for those challenging it,” said Bender.